In my race towards complete connected control of my house my Mitsubishi air conditioning inverter heat pump has been an outstanding item. I have been exploring various solutions but none of them has given me two way control. Late last year Mitsubishi introduced MELCloud. This post will cover some of the possibilities out there for controlling such appliances and a short review of Mitsubishis MELCloud.

WiFi Enabled Thermostats

One should think that the cold and unstable Norwegian climate would have resulted in priority of Wifi enabled thermostats like the Nest and Ecobee. Unfortunately they are not compatible with known standards in our region. These thermostats have been manufactured mainly for the US marked but has expanded to Europe lately. Mini Split heat pumps are not fully supported by Nest or Ecobee, There are some manufactures who have created adapters like this one. None of them seem to give me a complete functionality so i had to stop drooling and started to source other solutions.

SMS control in 2015?

There are also several ways of controlling heat pumps with add-on modules like the one above. Commonly they are controlled by a smartphone app but the signal to from the app to the unit itself is SMS based. The unit in the other end uses an IR blaster which sends the same IR signal as the heat pumps remote. The solution may work, but is it stable? And excuse me but controlling something by SMS is not quite modern day tech worthy. The other downside with a setup like this is that you only have a "simulated" two way communication. The app will give you the current setting based on the last sent setting.

Wifi Enabled IR control

We are getting closer, finally the IntesisHome both looks good and has created an AC controller which is Wifi controlled. This was closing in on becoming my preferred choice. The app looks great and the unit has gotten several great reviews. It even has support for IFTTT.com which is a service i love. But still it is IR based so you do not get two way communication and you have to have a box with a clear view of the AC unit for the IR signal to function.

I also played around with solutions like the Itach. A ethernet enabled IR blaster. The Itach is a really good product. It will learn IR codes from your original remote and lets you use the code from several different services through their open API. It works pretty well as a virtual device in my Z-wave enabled smart home controller. The only problem i experienced was that i was unable to learn all the codes from my original remote. Most AC units update all functions no matter what you click on the remote. So if you are only about to change the temperature it will still send a signal with an update on fan speed, mode etc. This means that the generated IR code will be very long. Just because it did not function properly with my set up, it may still work well in yours. Here is a guide to getting Itach working in Fibaro HC2.

Z-wave IR control

Remotec ZXT-120

Remotec has a Z-wave based IR device which has a wide range of supported devices. Unfortunately it previously had known issues with Fibaro HC2. I decided at the time to not buy it because of that. I have read lately that the unit is now supported by Fibaro HC2. The problem still as all of the above it is only one way control. Any changes made by the remote will not be updated in Fibaro or your preferred home controller like Vera, Zipato, Indigo or Smartthings.

Proprietary - Mitsubishi WiFi Adapter

Due to the lack of full support by the above covered items i was forced to buy the Mitsubishi WiFi adapter. Sounds like i am not fully satisfied? Well, that is partly true. So why am i not a happy puppy?

Installation

Installation was pretty straight forward. I had to remove the front cover on the AC. Remove the main controller board cover, slightly pull out the PCB and attach the adapter to connector CN105, it was easy to spot as they were both red.

There was plenty of space within the AC unit to have the adapter there rather on the outside.

To be able to use the device you need to have a WiFi router that supports WPS. Next step was to press the WPS button on the WiFi module and then WPS on the router or in the router software. The unit connected with great ease to my Netgear R7500.

Software

There are apps both for iOS, Android and web based. The setup was not overly complicated but definitely not as easy as many other internet enabled devices in modern time. It is fairly noticeable that Mitsubishis app is not the greatest in a design perspective, multiple graphic items were cut and cropped strangely and to be honest it does not look as "sexy" as i would have hoped. To set up the unit you first have to create an account. They do want to know quite a bit about you so this prosess is a bit time consuming. You then have to register the WiFi unit with the MAC address and ID code at the back of the unit.

The setup takes about 10 minutes so a bit more than optimal. It is not the only thing that takes time, even the adjustments of the unit itself takes time. Every change made in the app takes approximately 2 minutes to update in the cloud and to the unit itself, it is actually programmed to be this way on purpose.

So why is it like this? It seems as though Mitsubishi has som strong minded IT guys. The MELCloud has been programmed with the MELCloud in mind and not the actual control of the unit. I am guessing that the two minute delay is to make sure that the data in the cloud is the most updated data and that any command sent will be cued there and approved before it is sent to the unit. There is never at any point contact between the app and the unit directly. So is this a problem? Well not really in an automation perspective where everything is run in the background but for a user applying a change in the app and having to wait it is a bit annoying. Also for testing purposes towards home automation or similar it is time consuming.

The web interface looks pretty similar to the smartphone Apps. It looks clean and ok but nothing fancy. The Norwegian translation is also by an Japanese who has learned Norwegian and not by a Norwegian who speaks Japanese, google translate may also have been involved. The system does not play well with others either. Some 3.rd party vendors have access to MEL cloud but to my knowledge this has not been given to any home automation services. So complete control and access from IFTTT, Fibaro or similar is not going to be easy. I knew about this before i purchased the unit but i also knew about a group of people who had been playing around with Wireshark to sniff out the data to and from the unit and doing some reverse engineering (use google translate). It seems doable to be able to program Fibaro to control the unit in some form. But i am hoping by time that Mr.Mitsubishi or a major player in the game creates a more open form of control. It surprises me that a large manufacturer like Mitsubishi is so restrictive to being more open and weaving it together with other common home appliances.

Summary

Mini Split heat pump control is not up to standard in my mind. There are some manufacturers out there handling it better than Mitsubishi but still not as good as it could have been. The adapter i got fulfills most of my needs for the control of the unit. It is not controlled by SMS or any other ancient form of communication. It allows me to remotely control the unit when i see the need. It gives me two way control meaning i can still pick up the old remote and do my adjustments and the app will be updated with these adjustments. The remote will off course update all settings so i have to set it to the right mode etc. Despite having a semi updated remote this is the most complete solution i have been able to find. In Norway retailers demand over 4000,- NOK for the unit. I was able to find it on Ebay for 1400,- NOK. Retail price in Norway is far to much according to functionality in my mind. What heat pump have you got and how is it controlled? Let me know in the comment section below.

Did you consider modbus as part of your solution? I'm running the IR remote, but think modbus would probably be a better solution.

Regards,
Espen Leknes

Reply

Stian

1/10/2015 09:33:11 am

Modbus would problably be a good way to go. I chose the adapter i chose because i knew people had come quite far in the reverse engineering so i am hoping it will have an increased functionality in a while :)

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Søren Raarup

29/9/2016 06:32:52 am

Found a nice list of KNX interfaces for a lot of AC brands
https://www.voltus.de/hausautomation/knx-eib/systemgeraete/gateways/intesis/knx-series/

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Pete Cole

26/11/2015 06:06:07 am

Excellent and informative article, one note if you contact Mitsubishi Electric Support, they can remotely reduce the max update time to max 1 minute (on user by user request basis).

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Stian Øien

26/11/2015 08:42:25 am

Hei Pete.

Thank you very much for the tip.

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Lars Kristian

14/1/2016 06:24:29 am

Hi, Have you tough about using interface unit made by Mitsubishi for heat pumps so it can be controlled by WiFi Enabled Thermostats and then communicate the thermostat with Smarthings/Fibaro?

Wow, no I have not seen that before. Thank you very much. I will definitely assess going down that route as the current setup is still half way... Again, thank you.

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Tdogas

17/8/2018 02:03:03 am

Hi, are there some news about reverse engineering and WiFi module? After 2 years of your post I'm having same problems, and can't find any solution :(

Søren Raarup

29/9/2016 06:15:47 am

Link did not work.
This one does.
http://www.mitsubishielectric.ca/en/hvac/PDF/city_multi/CM_SB/SB_PAC-US444CN-1_Thermostat_Interface_201603.pdf
Great solution. I'll see if I can find such device for Panasonic.

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Søren Raarup

29/9/2016 07:09:53 am

On Amazon
https://www.amazon.com/Mitsubishi-Electric-Thermostat-Interface-R2/dp/B01BNW6PZM/ref=sr_1_3

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Jeff

8/2/2016 10:26:32 am

I've decoded the protocol for the Mr. Slim IR controls (at least the US variant I have) and it's something of a mess. Python libraries and an ESP8266 let me "blast" the IR. Of course, there is no feedback about the unit's state or successful receipt of a command (past the beep).

I'd prefer direct wire through the CN105 connector. Have you taken a 'scope to the pins there to see what the protocol is? At least avoiding the IR and being able to pull supply voltage from the wall unit would make the custom hardware simpler and a lot more robust.

Jeff

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Stian Øien

8/2/2016 12:10:59 pm

I have not, but I would assume it is modus. Mitsubishi have now released an adapter using the same port for 24v thermostats so you can now use Nest, Ecobee etc.

Was anyone ever able to get one of those 24V thermostat interfaces? (PAC-US444CN-1) I've been looking into it more and more, and am wondering if anyone's been able to decode the UART command sequence it uses.

Someone posted an awesome hack using the CN105 connector, but it still relies on the Heat Pump's temperature sensor. https://nicegear.co.nz/blog/hacking-a-mitsubishi-heat-pump-air-conditioner/

Can the Flair turn off the unit entirely after it hit set temperature and on when hysteresis is passed ? or will the fan stil blow in "Flair off" mode ?

Currently, it will hit the hysteresis limit and turn the unit off and then flip it back on the other side of hysteresis window. This assumes the system is in auto mode. If in manual mode, it will use the minisplits internal temperature regulation scheme which as you know, isn't particularly accurate. We will add some options in the future but thats how its currently set up. Hope that helps and let me know if you have any additional questions.

Take a look at the Ambi 2nd edition (this one have weather compensation)
https://www.kickstarter.com/projects/ambi-labs/ambi-climate-2-ai-enhanced-air-conditioning-comfor

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Anthony

21/12/2017 11:36:17 pm

Sorry, but IntesisHome's IR sollution is actually bidirectional!
Any command you send with your IR remote controller will be captured by IntesisHome device, and the status are updated in the IntesisHome side :-)

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Emil

17/8/2018 02:18:59 am

Currently the most userfriendly setup is the Ambi Climate 2nd:
https://www.ambiclimate.com/en/